In homes as well as in certain industrial applications, a single tap outlet is used to dispense liquids from two or more faucets which are most often manually controlled. The most common tap outlet used is the one for cold and hot water installed over a sink in kitchens, washrooms, etc.
The drawback of single tap outlets is that the faucets have to be adjustably opened and shut each time the tap is needed. For some people, this can be a nuisance resulting in impatient adjustment of the faucets and, consequently, a flow of water which is, for example, in a kitchen excessive and/or too hot or too cold. In industrial uses of such taps, a worker may have a similar reaction again resulting in a liquid flow which does not correspond to the operational requirement and which wastes liquid.